There are many situations where it is necessary for a storage system, machine or other type of structure to be level. The problem is exacerbated when the floor on which the structure is installed is uneven. In cases where the structure is particularly heavy, a structure that is initially level may, do to the weight of the structure, become unlevel over time. It is therefore advantageous to provide a leveling foot under the structure that can be adjusted to achieve a level installation.
A known solution to the problem is to provide an adjustable foot of the type having a threaded shaft that can be extended or retracted to compensate for an uneven floor. Such solutions are well known in common household appliances, and can be illustrated by the device shown in U.S. Pat. No. 3,436,045. KR 2014 0122920 shows a height adjusting device wherein the height is adjusted as a second body is inserted into a first body comprising a spring wherein a stopper is inserted into the second body to limit movement between the two bodies. A disadvantage to such thread-based solutions is that the threads of the foot must bear the weight of the structure. This may lead to device failure where the structure is very heavy.
It also known to use a wedge to level a structure, its simplest form of the type described in U.S. Pat. No. 5,249,767. A simple wedge, however, is not self-adjusting and can be difficult or impossible to remove once the weight of the structure bears down upon the wedge.
Another known solution is described in U.S. Pat. No. 7,744,049. This device uses a spring to press open a foot attached to an elongated shaft. While this device has the advantage of being self adjusting during installation, it suffers from the disadvantage of using a thin shaft to bear the weight of the structure, which can lead to failure when the structure is particularly heavy.